I'm having trouble making HiDPI work on my MacBook Pro (13" 2015 with Retina, Mojave up-to-date).

I plugged it into a 1440p Dell U2719D, which works fine out of the box, except that fonts look ugly (too small) and the UI is small as well. I tried enabling HiDPI resolution, for example 1280x720 (perfect 2 for 1).

Here are my findings:

  • HiDPI resolutions are simply not available in the system's menu in this setup. I tried the hack (for example here), but there is no way to make them appear in the system's Display Preferences. 720p is listed there but it's not HiDPI and looks ugly.

  • Using RDM, I'm able to see many more resolutions, including HiDPI resolutions. However, among HiDPI resolutions, only 16:10 resolutions work (1680x1050, 1440x900, 1280x800 etc.). For all other, HiDPI, non 16:10 resolutions, I click on them in RDM, nothing happens. (I also tried other resolution managers with the same effect).

It's worth noting that the 13" built-in display is 16:10 (at 3360x2100 native, 1280x800 scaled). 1280x800 looks fine but the black borders are weird (and it's not perfect 2 for 1 pixels).

Is this behaviour normal? Is this a bug or lack of feature? Is there a workaround?

After some careless tinkering (notably using this link), the HiDPI resolution "1281x720" appeared (!) which actually works (!!). It's not perfect but it looks sharp and uses most pixels on the display.

  • A 27" 1440p screen isn't actually HiDPI, it's 'standard', so reducing resolution will just do it 'the old way'. On mine I see 2560x1440, 2048x1152, 1600x900, 1344x756, 1080 & 720 as alternatives, all 16:9 ratios.
    – Tetsujin
    Commented Sep 23, 2019 at 6:27
  • As far as resolutions are concerned, yes. But fonts look horrible in 1440p because they're too small, hence the HiDPI mode. It's true that 720p makes them look too big, probably 1080p would be better. Still, the fact that 16:10 HiDPI resolutions work and not 16:9 is weird.
    – maxbc
    Commented Sep 23, 2019 at 14:00
  • I've no idea why it can only see 16:10 resolutions; but again, this is not HiDPI, this is just regular old-fashioned resolution changing.
    – Tetsujin
    Commented Sep 24, 2019 at 12:44
  • Well I'm using a generalization of the "official" HiDPI definition (if that's even a thing). HiDPI is 2 pixels for 1, but the same anti aliasing principles can be applied to any ratio, albeit with various results. Basically, applications including the UI "see" a lower resolution, but the system actually renders to native monitor resolution in the backstage resulting in crisp text/images yet big UI. If this has another name, I'll gladly use it but it seems everyone is using "HiDPI" for exactly this. It's definitely not mere resolution changing.
    – maxbc
    Commented Sep 25, 2019 at 13:30
  • 1
    @maxbc Your update is really helpful. It'd be great if you can put that as answer. Commented Feb 9, 2022 at 14:26

1 Answer 1


As stated in the updated question, what finally worked for me was using instructions provided in this link to create a custom scaled resolution of 1281x720 (since the 1280x720 was not working). It works really well and there's not blur or visible difference of quality compared to other (working) 16:10 scaled resolutions.

In summary:

  • Enable HiDPI with sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true
  • Detect VendorID / ProductID for your monitor
  • Use the generator provided in the link to generate a custom resolution for your monitor (mine was 1281x720) in the .plist format (you can remove most resolutions and just use one custom resolution)
  • Download the .plist and execute the following while replacing vendorID and productID (4-digit hexadecimal numbers) with your own:
    sudo mkdir -p /Library/Displays/Contents/Resources/Overrides/DisplayVendorID-10ac
    and place the .plist inside
  • Restart the Mac and use RDM to select the relevant resolution
  • 1
    It would be helpful for anyone coming across this answer in the future if you could summarize the link in case it becomes broken.
    – agarza
    Commented Feb 10, 2022 at 17:55

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